FYHist4.txt
Dear Friends,
The reports of pilots who put in the effort to clear their vision from
20/60 to 20/20 (about -1.25 diopters to zero diopters) are correct.
But it does take a strong belief in yourself and to recognize the value of
your distant vision to you. This takes will-power and commitment.
If you have commentary, or wish to suggest changes please let me know.
While plus-prevention is difficult -- it is possible. And that
is what we should learn from science and the second-opinion
on the subject.
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Subject: My tribute to Francis Young's scientific work.
Re: A Summarization about what is possible -- in the future.
I met Francis Young after being invited to a meeting of
behavioral optometrists by Dr. Ron Berger in 1977.
I thought it would be of great value to understand Francis
Young's work since I judged that the correct answer concerning the
eye's behavior had to come from science and the facts.
In our published works, I always solicited an expert in the
given field of study. My interest is in engineering and science,
and the facts as they can be understood.
In 1995 Francis sent me his published works, but since I was
working full time I had no time to review them in detail.
There is some very valuable information in the Eskimo data
that is essential for understanding the behavior of the
fundamental eye (and its refractive STATES) that simply has not
been digested.
The primate studies show the same behavior as the Eskimo
eye. To briefly summarize the refractive STATES of the
fundamental eye:
1. Primates in the "wild" have positive refractive STATES that
are positive, by about +0.7 diopters with a Standard
Deviation of 0.7 diopters. This means that 96 percent of
the refractive STATES range from -0.8 diopters to +2.1
diopters. (Note: Because this was a CYCLOPLEGIC
measurement, the -0.8 diopter primate had excellent vision.
This is a artifact of a cycloplegic measurement RATHER than
a Snellen measurement.)
2. Eskimos in the "wild" have a positive refractive STATE that is
positive, about +1.8 diopters with a Standard Deviation of
1.3 diopters This means that 96 percent of these Eskimos.
had excellent vision, with the range being from -0.8
diopters to +4.4 diopters. (Again the difference between
cycloplegic measurement does NOT mean that the -0.8 disputer
Eskimos did not good vision.)
A discussion of the refractive STATES of the fundamental eye in a long-term
"near" environment:
It must be stated that there is no QUANTATIVE
measurement of "near" or "far" environments. This is the problem
of judging HUMAN populations. Only in an experiment where you can
CONTROL the accommodation system -- with a negative lens -- can
you develop an accurate model for the natural eye's behavior.
1. Primates kept in a caged environment for seven years or more
had an AVERAGE negative refractive STATE. The average is
-1.6 diopters with a Sigma, or Standard Deviation of 4 diopters.
2. Eskimos in a "reading" environment have a refractive STATE of
-2.1 diopters and a Standard Deviation of 2 diopters.
Basically what happens is that when a population of
fundamental eyes are placed in a long-term "near" environment, the
refractive STATE "follows" the change in ACCOMMODATION (as a
natural process), and the Standard Deviation (Sigma) will broaden.
BACKGROUND FOR A PREVENTION STUDY
(Key Words: Average, Mean, Sigma, Standard Deviation, Long-term)
Why is this information important?
In a number of studies Francis Young recorded:
1. The average value of refractive STATES for the population.
2. The Standard Deviation, and
3. The absolute range of refractive STATES.
In Dr. Young's bifocal study he failed to record the Sigma,
which is a serious omission in my judgment. I can
estimate it to be about 1.8 diopters, but in any future proposed
study of PREVENTING a negative refractive STATE, collecting that
information would be of crucial importance.
The results of the bifocal studies. What the control-group
showed (in six studies) was that the un-protected refractive STATE
went down by -1/2 diopter per year.
Therefore any SUCCESSFUL preventive study must show a growing
DIFFERENCE between the test group and the control group DIFFERENCE
of 1/2 diopter per year.
The claim of the majority-opinion is that the Oakley-Young
study was a "fluke", and that the preventive-plus had NO EFFECT on
the eye's refractive state. I Strongly disagree with that
judgment of the eye's behavior.
Francis Young showed a growing difference between the test
and control groups of 1/2 diopter per year. This "plus" study was
maintained for four years, so the difference became 2 diopters.
Thus, my judgment is that his values are correct, and if a
more forceful effort were made with the plus it could lead to
successful prevention in a four year college.
The question is this -- HOW DO YOU DO IT?
That becomes the real issue for all of us.
The current Majority-opinion judgment about the Oakley-Young
study is this:
1. The natural eye is NOT dynamic and that, therefore,
2. The natural eye will not change its refractive STATE by -2
diopters in four years in a "school" environment.
Given the fact that objective scientific experiments show
that the natural eye changes it refractive STATEE when a -3
diopter lens is placed on it, thus proving the dynamic quality of
the natural eye, there is reason to believe that the Oakley-Young
study was accurate in representing the effect that a plus could
have in preventing the development of a negative refractive STATE
for the fundamental eye.
But is should also be strongly stated that the person himself
must be intellectually involved in this type of work, suggesting
that the person should go through an educational process before
any steps are taken (for prevention) in the first place.
Using the Standard Deviation values established by Francis
Young, we can now calculate the most probable outcome of a study
where the students have enough knowledge of these issues, (and of
the behavior of control-system) to take strong actions for their
own long-term personal welfare.
We can only anticipate the "future" by knowing the results of
PREVIOUS scientific studies. Thus by understanding the
limitations (and constraints) of the Oakley-Young study we can set
certain standards.
1. The study would required about 50 students in the "control
group", and 50 in the plus group. The total number of eyes
would be 200.
2. The difference between the "do nothing" group must be compared
with the plus group in terms of refractive STATE.
3. The refractive STATE will be determined by the person himself
(first) and will be checked by some competent third-party.
4. The effort will rely on the technical competence of the person
himself, an his collective judgment.
5. His knowledge of statistics is essential.
With the above UNDERSTOOD, then the following restrictions
would be applied.
1. Visual Acuity of no worse than 20/70. (This Visual Acuity
must be capable of being cleared with a minus lens no
stronger than -1.5 diopters.)
2. No "promises" will be made -- but the students will have
access to all information that they ask for.
Plus-prevention will be described as the second-opinion.
3. A "back up" plan will be available, which will be
vision-clearing with a Ortho-K lens -- after the study is
completed. The goal is that the person will get very close
to 20/20 with the plus, and it will be an option of the
person himself if he judges that the use of Ortho-K is
necessary.
Using the above conditions, we can calculate the expected
standard deviation and change in mean value of refractive STATES.
The Sigma will be close to 1 diopter. I would be about 1 diopter.
When the seven months are completed, the DIFFERENCE in refractive
STATE can be expected to be at least 1/2 diopter.
The equation is basic statistics:
Z = (Xc - Xp) / Sqrt [ Sigma-c ^ 2 / Nc + Sigma-p ^ 2 / Np ]
Where Z is the "confidence" level for the results.
Any value above Z = 3 is virtually certain.
Z = ( -1/4 -1/4 ) / Sqrt [ 1 / 100 + 1/ 100 ]
Z = 3.5
Using basic values, a difference of 1/2 diopter will show the
effectiveness for the plus FOR PREVENTION.
Obviously the competent judgment will be held by each of the
individuals in this study.
I believe that this is a reasonable scientific approach to
supporting a pilot with plus-prevention.
Ultimately this work will always depend on the judgment of
the person himself at to the necessity of continued use of the
plus for prevention.
Best,
Otis